You could always try mixing a bit of canned with his kibbles
He may still be too nervous to eat much, it's impossible to say, really. Are you leaving the kibble down all day long? If so, it would probably entice him to eat more if you just fed him 2 or 3 times a day instead. I was free-feeding my girls for a long time, but my little one didn't eat much that way, so I've started giving them some canned twice a day to ensure that little Luna was getting some food into her, she was getting too skinny
Anyway, it's going to take time, and switching foods too much could create a more picky eater. Try hand feeding him a few pieces to get him started, and maybe sit next to his bowl while he eats. I'm not an expert by any means, just relaying what's worked for me in the past.
Good luck with your new little cutie
